Question

我有两个表JOB和EMP；值是这样的

CREATE TABLE JOB (JOBID SMALLINT UNIQUE NOT NULL,JOBNAME CHAR(15));
CREATE TABLE EMP(EMPID SMALLINT, JOBID SMALLINT, SAL SMALLINT, CITYID SMALLINT);

INSERT INTO JOB(JOBID, JOBNAME) VALUES
        ( 1, 'DEVELOPMENT'),
        (2, 'DEVELOPMENT'),
        (3,'TESTING'),
        (4,'TESTING'),
        (7,'TESTING'),
        (9,'RESEARCH'),
        (8,'HR');

INSERT INTO EMP (EMPID , JOBID, SAL,CITYID) VALUES
   (  100,1,1000,10),
   (  200,2,2000,10),
   (  300,1,2500,20),
   (  400,3,1000,10),
   (  500,6,3000,10),
   (  600,8,1000,30),
   (  700,8,2000,10)
;

我想显示所有工作名称计数和平均工资；作业名称（如果不存在作业ID）则显示0

对于给定的城市ID（Emp表），获取每个作业名称的所有jobid（来自job表），并在Emp表中匹配（如果存在显示计数）（Emp表中存在的jobid的数目），而avssal否则为0，表示count和avgsal 。结果应该按照作业表中作业名称的顺序排列。输出应该是这样

Cityid  jobname        count avg-sal
10       development    2     1500
10       TESTING        1     1000
10       RESEARCH       0      0
10       HR             1      2000
total                   4      1500
20      development     1      2500
20      Testing         0      0
20      Research        0      0
20      HR              0      0
Total                   1     2500
Grand Total             5    1700

我尝试通过联接，但是无法正常工作；使用join或Cursor更好吗？

Answer 1

这是您想要的吗？

select 10 as cityid, jobname, count(e.empid) as cnt,
       avg(e.sal)
from jobname j left join
     emp e
     on e.jobid = j.jobid and e.cityid = 10
group by grouping sets (jobname), () );

SQL查询将表1匹配到表2

1 个答案: